The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this natural-color image of the Caspian Sea on June 4, 2010

What is a Closed Lake?

Caitlin Dempsey

Closed lakes are bodies of water that do not drain into an ocean or river.

The color of water is a by product of how light is absorbed. Mangrove islands bespeckle the bay in upper Lostman's River. Photo: Paul Nelson, U.S. Geological Survey. Public domain.

Rivers in the United States are Changing Colors

Caitlin Dempsey

A team of researchers analyzed Landsat images over a 38-year period and found that a significant number of large U.S. rivers are changing colors.

Haloarchaea are salt-loving microorganisms that impart the pink and red colors of Lake Natron in Tanzania. Image: Landsat 8 acquired March 6, 2017.

This Lake is Home to the Highest Concentrations of Lesser Flamingos in East Africa

Caitlin Dempsey

The protective salt marshes that ring Lake Natron in Tanzania have nurtured the highest concentrations of lesser and greater flamingos in East Africa.

Laguna Grande is a 50-hectare salt-water lagoon located in the municipio of Fajardo, in the eastern-most tip of Puerto Rico. Photo: USGS.


Elizabeth Borneman

Limnology is an area of geography that studies bodies of water located inland such as lakes, rivers, wetlands, streams, watersheds, and reservoirs.

Aquatic Dead Zones

Caitlin Dempsey

Aquatic dead zones are bodies of water where the oxygen conditions are so low that marine life is unable to be supported.